I understand the OCD with a black car. I used to have a 2001 Corvette that was red -- almost as bad as black -- and I never drove the damned thing because I was so afraid of damaging the paint. I also had a black Mazda CX-7 that looked awesome when clean but terrible otherwise and I just let that one go. Both of these cars are a large part of the reason why I went with a Brilliant Silver Z. You can barely see swirl marks (if even at all) and the paint looks great even when the car's dirty. Now I can enjoy driving my car and sleep well at night.
All this being said, I've been pleasantly surprised with the Majestic Blue paint on my '08 Altima. The car has 32K miles on it and other than the front bumper (which is loaded with rock chips from highway driving) it looks great. There's nary a swirl mark or scratch and any other rock chips are minor and are simply a result from highway driving. From more than five feet away the car looks spectacular and even when you're closer than that you really have to look to see the flaws. If my Z fares this well I'll be in hog heaven!